Alcohol and weight loss
Is alcohol affecting your goals of losing fat-mass?
The short, sharp, simple answer is yes haha. I think it’s relatively common knowledge that alcohol is not healthy for you, but this week I wanted to nerd out on you for a bit and explain exactly why it’s limiting your ability to lose fat mass and how your body processes alcohol. This weeks blog will be a bit shorter than previous blogs, but I wanted to fill it with a bit of education!
Okay, nerd-out time!
Alcohol and calories:
Alcohol is calorie dense, it has an energy density of about 29 kJ/g (7 kcal/g). This means that it contributes significantly to total daily energy intake.
A review of the impact of alcohol on energy intake by Yeomans (1) found that all the research to date fails to show a reduction in food intake in response to alcohol ingestion either before or with a meal. This means, that you are still eating just as much food throughout the day, but then also drinking extra energy in the form of alcohol. A lot of people will also drink with their meal and therefore gaining a double up of energy intake.
Therefore, to consume alcohol you must reduce your consumption of energy from other dietary components in order to maintain an energy balance.
Physiology of fat burning and how alcohol affects this:
Alcohol consumption causes a rapid rise in alcohol oxidation until all the alcohol is cleared from the body. This means that alcohol is used preferentially as an energy source over other substrates and can suppress the oxidation of fat and, to a lesser degree, that of protein and carbohydrate (2).
Alcohol is not converted to triglycerides and stored as adipose tissue, meaning that it is not directly stored in our bodies as fat, it also can’t contribute to the formation of muscle or liver glycogen (useful energy stores). It may, however, indirectly divert dietary fat to storage by providing an alternative and preferred energy source for the body (3). Put simply, the body prioritises clearing alcohol from your system, so while this is happening it is not metabolising your other energy stores. So, you are more likely to store the energy you gain from food as fatty tissue as it is not ‘burned’ by your body.
Therefore, apart from leaving you hungover and making your liver work overtime, alcohol is most likely one of the contributing factors to your lack of loss in fat-mass.
1. MR Yeomans - British Journal of Nutrition, 2004
2. J J Shelmet, G A Reichard, C L Skutches, R D Hoeldtke, O E Owen, and G Boden - The Journal of Clinical Investigation, 1988